1. Field of the Invention
The present invention provides arrays of oligonucleotide probes immobilized in microfabricated patterns on chips for analyzing molecular interactions of biological interest. The invention therefore relates to diverse fields impacted by the nature of molecular interaction, including chemistry, biology, medicine, and medical diagnostics.
2. Description of Related Art
Oligonucleotide probes have long been used to detect complementary nucleic acid sequences in a nucleic acid of interest (the “target” nucleic acid). In some assay formats, the oligonucleotide probe is tethered, i.e., by covalent attachment, to a solid support, and arrays of oligonucleotide probes immobilized on solid supports have been used to detect specific nucleic acid sequences in a target nucleic acid. See, e.g., PCT patent publication Nos. WO 89/10977 and 89/11548. Others have proposed the use of large numbers of oligonucleotide probes to provide the complete nucleic acid sequence of a target nucleic acid but failed to provide an enabling method for using arrays of immobilized probes for this purpose. See U.S. Pat. Nos. 5,202,231 and 5,002,867 and PCT patent publication No. WO 93/17126.
The development of VLSIPS™ technology has provided methods for making very large arrays of oligonucleotide probes in very small areas. See U.S. Pat. No. 5,143,854 and PCT patent publication Nos. WO 90/15070 and 92/10092, each of which is incorporated herein by reference. U.S. patent application Ser. No. 08/082,937, filed Jun. 25, 1993, describes methods for making arrays of oligonucleotide probes that can be used to provide the complete sequence of a target nucleic acid and to detect the presence of a nucleic acid containing a specific nucleotide sequence.
Microfabricated arrays of large numbers of oligonucleotide probes, called “DNA chips” offer great promise for a wide variety of applications. New methods and reagents are required to realize this promise, and the present invention helps meet that need.